Conventionally, among electrically powered vehicles capable of generating vehicle driving power using electric power from power storage devices provided therein, there has been used an electrically powered vehicle including a power generating structure that charges the power storage device during vehicle traveling. A representative example thereof is a hybrid vehicle that employs an output of its internal combustion engine to generate electric power to charge the power storage device provided in the vehicle. An alternative example thereof is a fuel cell vehicle having a fuel cell mounted thereon because such a fuel cell vehicle is capable of charging its power storage device using a fuel cell during vehicle traveling and therefore can be regarded as a hybrid vehicle in a broad sense.
In the description below, a vehicle employing electric power from its power storage device to generate vehicle driving power and including a power generating structure for charging the power storage device of the vehicle during vehicle traveling will be referred to as “hybrid type electrically powered vehicle”.
In such a hybrid type electrically powered vehicle, charging and discharging of the power storage device are performed repeatedly during traveling. Accordingly, control is required to manage a state of charge (SOC) of the power storage device during the vehicle traveling. Generally, using the above-described power generating structure, the power storage device is appropriately charged during the vehicle traveling, thereby controlling the SOC so as not to fall out of a predetermined control range.
As one manner of controlling the SOC in such an electrically powered vehicle, Japanese Patent Laying-Open No. 2007-62640 (PTL 1) describes a hybrid vehicle that controls the SOC of its power storage device in consideration of status of use of electric power in a destination. According to PTL 1, in consideration of the status of use of electric power in the destination, a driver sets a target SOC. Thereafter, traveling is started with the power storage device of the vehicle being in a fully charged state. Until the SOC reaches the target SOC, an EV (Electric Vehicle) mode is selected such that the traveling is performed using only a motor generator with the engine being stopped. After the SOC reaches the target SOC, transition is made to a HV (Hybrid Vehicle) mode in which the traveling is performed using the engine and the motor generator. In this way, the SOC of the power storage device is maintained at the target SOC.